<!DOCTYPE HTML>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <title>Html和CSS的关系</title>
  <style type="text/css">
    h1{
      font-size:12px;
      color:#930;
      text-align:center;
    }
  </style>
</head>
<body>
<h1>Hello World!</h1>
</body>
</html>